textproduct: Rapid City

KEY MESSAGES

- Gusty northwest winds Wednesday.

- Very cold temperatures Thursday night, Friday and Friday night.

DISCUSSION

(This Evening Through Tuesday) Issued at 318 PM MST Tue Jan 20 2026

Upper level analysis has a ridge of high pressure over the West Coast with a wide trough over most of the CONUS from the Rockies east. This is resulting in northwest flow across the forecast area. At the surface, a cold front is oriented west to eat just south of the area - across northern Nebraska. Snow is falling over the northern Black Hills due to upslope conditions, with recent reports indicating 2 to 4 inches of snow has already fallen. Northwest winds remain gusty across the northwestern South Dakota Plains and around western Fall River County, where speeds are averaging around 30 mph and gusts are 45 to 50 mph.

For tonight, upslope snow will gradually end this evening, with another 1-2 inches possible over the Northern Black Hills. Will forgo any advisories, since most of the snow has already fallen.

A strong shortwave and another cold front begins to move through the forecast area very early Wednesday morning (~10Z) and races through the entire area by 18Z. Pressure rises of 3-7mb/3hr are common behind the front. As far as wind speeds, HREF and ensemble guidance are indicating a 50-90% chance of wind gusts >50mph with less than a 15% chance of wind gusts exceeding 60mph. Sustained wind speeds follow a similar trend between warning and advisory criteria. Therefore, have issued a wind advisory for the South Dakota Plains/northeastern Foothills for Wednesday.

As far as snow is concerned, not expecting much new snow as moisture is limited. Snowfall over the plains today was minimal, less than an inch in most spots. Therefore, added some patchy blowing snow to the forecast, but decided against winter weather advisory for this reason.

For Thursday and Friday, a 1051mb surface high will bring arctic air into the Northern Plains. The forecast area will be on the western edge of the coldest air, so confidence in strength of arctic air is still in question. Right now, Friday looks to be the coldest day with highs on the South Dakota Plains in the single digits above and below zero.

Looking toward the weekend, we'll continue to be on the edge of the coldest air with temperatures spreads 15-25F, but with mean temperatures increasing. Confidence in details remain low.

AVIATION

(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 414 PM MST Tue Jan 20 2026

Gusty northwest winds with gusts 30-45 knots will persist across NE WY and western SD through the forecast period. Transient MVFR/IFR conditions possible through 21/00-02Z as bands of light snow/flurries push through the region. Expect VFR conditions to follow.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory until 6 PM MST this evening for SDZ001-012-013-031- 041-072-073. Wind Advisory from 3 AM to 5 PM MST Wednesday for SDZ001-002-012- 013-025-072-073-078. Wind Advisory from 5 AM MST /6 AM CST/ to 5 PM MST /6 PM CST/ Wednesday for SDZ014-026-030>032-041>044-046-047-049- 075>077. WY...None.